Lipid-based nanotubules for controlled release of healing agents in golf ball layers

ABSTRACT

A golf ball including a core and a layer disposed concentrically about the core; wherein at least one of the core or the layer is formed of a polymer composition including a lipid-based nanotubule-encapsulated healing agent; the healing agent being present in an amount between about 0.1% and about 20.0% of the composition by weight.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of co-pending U.S.application Ser. No. 10/358,923, filed Feb. 5, 2003, which claimspriority to U.S. Provisional Application No. 60/403,923, filed Aug. 16,2002. This application is also a continuation-in-part of co-pending U.S.application Ser. No. 10/176,720, filed Jun. 21, 2002, which claimspriority to U.S. Provisional Application No. 60/300,124, filed Jun. 22,2001.

FIELD OF THE INVENTION

The present invention relates to golf balls and, in particular, to golfballs components formed form compositions comprising lipid-basednanotubules for controlled release of healing agents.

BACKGROUND OF THE INVENTION

Golf balls can generally be divided into two classes: solid and wound.Solid golf balls include one-piece, two-piece (i.e., solid core and acover), and multi-layer (i.e., solid core of one or more layers and/or acover of one or more layers) golf balls. Wound golf balls typicallyinclude a solid, hollow, or fluid-filled center, surrounded by tensionedelastomeric material, and a cover. Solid balls have traditionally beenconsidered not only longer and more durable than wound balls, but alsolacking a particular “feel” provided by the wound construction that waspreferred by accomplished golfers.

By altering solid ball construction and composition, however,manufacturers have learned how to vary a wide range of playingcharacteristics, such as resilience, durability, spin, and “feel,” eachof which can be optimized for various playing abilities. Thisimprovement in construction technology has allowed current solid golfballs to provide feel characteristics more like their woundpredecessors. The golf ball components, in particular, that manymanufacturers continually look to improve are the center or core,intermediate layers, if present, and covers.

Golf ball cores and/or centers are typically constructed withpolybutadiene-based polymer compositions. Compositions of this type areconstantly being altered in an effort to provide a higher coefficient ofrestitution (“COR”) while concurrently lowering compression which, inturn, can lower the golf ball spin rate, provide better “feel,” or both.

Manufacturers also address the properties and construction of golf ballintermediate and cover layers. These layers have conventionally beenformed of ionomers and ionomer blends of varying hardness and flexuralmoduli. The hardness range of ionomers is limited and even the softestblends can suffer from a “plastic” feel. Recently, however,polyurethane-based materials have been employed in golf ball layers and,in particular, outer cover layers, due to their softer “feel”characteristics, without a noticeable loss in resiliency and/ordurability.

There remains a need, however, for improved golf ball center, core,layer, cover, and coating materials. Therefore, the present invention isdirected to the use of novel, lipid-based nanotubules blended into thepolymers or coatings/adhesives from which golf ball components areformed. The nanotubules are “loaded” (filled) with active agents, suchas UV absorbers, light stabilizers, bleaching agents, dyes,fluorophores, and/or healing agents, to name a few, for the controlledrelease of these compounds during the life of the golf ball. It isenvisioned that certain compounds may be selected that can prolong theuseful life and performance of a golf ball because they are being“replentished” as a function of time.

SUMMARY OF THE INVENTION

The present invention is directed to a golf ball comprising a core; anda cover layer disposed concentrically about the core; wherein at leastone of the core or the cover is formed of a polymer comprisinglipid-based nanotubules in which an active compound ismicroencapsulated. In one embodiment, the cover includes the lipid-basednanotubules. The cover can be an outer core layer, an inner cover layer,or an outer cover layer. The core may be a single layer or include acenter and an outer core layer. Either may include the lipid-basednanotubules of the present invention. In a preferred embodiment, thecenter and/or core composition includes an organosulfur compound.Preferably, the core has an outer diameter of between about 1.5 inchesand about 1.62 inches and the cover layer preferably includes an innercover layer and an outer cover layer, at least one of which contains thelipid-based nanotubules.

The polymer containing the nanotubules thermoplastics, thermosets,ionomers, non-ionomers, polysaccharides; polyesters; polyamides;polypeptides; polyurethanes; polyureas, polyethylenes; polypropylenes;polyvinylchlorides; polystyrenes; polyphenols; polyvinyl pyrollidones;polyvinyl alcohols; ethylcelluloses; gar gums; metallocene-catalyzedpolymers; polyvinyl formal resins; water soluble epoxy resins;urea-formaldehydes; polylysines; chitosans; polyvinyl acetates; andpolymers containing α,β-unsaturated carboxylic acid groups, or the saltsthereof.

Preferably, the acid groups have been 100% neutralized by an organicacid or a salt, a cation source, or a suitable base thereof. In apreferred embodiment, the active compound has a diameter and thenanotubules have an inner diameter between about 2 to about 1000 timesthe diameter of the active compound. Ideally, the nanotubule has aninner diameter between about 20 to about 500 times the diameter of theactive compound. The nanotubules are preferably configured to releasethe active compound at a constant rate. Additoinally, the nanotubulesmay further include a solubility modifier in an amount sufficient toalter the rate of release of the active compound. The active compoundshould have a sufficiently low viscosity to facilitate loading thenanotubules by capillary action. The active compound may also include UVabsorbers, light stabilizers, bleaching agents, fluorophores, healingagents, catalysts, reactive identifiers, inks, dyes, and indicators.

In one embodiment, the nanotubules have an inner diameter of from about50 nm to about 20 μm and, more preferably, from about 100 nm to about 1μm, and most preferably, from about 200 nm to about 800 nm. In anotherembodiment, the nanotubules have a length of from about 1 μm to about 1mm, more preferably, from about 10 μm to about 200 μm. The polymer thatcontains the nanotubules preferably includes between about 5% and about70% nanotubules.

In another embodiment, a coating layer including the nanotubules ispresent. The coating may be formed from paints, primers, adhesives,urethanes, epoxies, or dyes and can be applied by roller, brush,dipping, or spray.

The cover layer is formed by compression molding, injection molding,casting, or reaction injection molding. Preferably, the cover layer isan outer cover layer and includes polyureas, polyurethanes,polyurethane-ureas, polyurea-urethanes, or epoxies. Ideally, thepolyureas, polyurethanes, polyurethane-ureas, polyurea-urethanes, orepoxies are aliphatic or saturated. In an alternative embodiment, thegolf ball has a coefficient of restitution of greater than about 0.8.

The present invention is also directed to a golf ball comprising a core;an intermediate layer disposed about the core; a cover disposed aboutthe intermediate layer; and a coating layer; wherein the cover iscomprised of lipid-based nanotubules comprising UV absorbers, lightstabilizers, bleaching agents, fluorophores, healing agents, catalysts,reactive identifiers, inks, dyes, or indicators for controlled releaseinto at least one of the adjacent intermediate or coating layers.

The present invention is further directed to a golf ball comprising acore; and a cover layer disposed concentrically about the core; whereinat least one of the core or the cover is formed of a polymer comprisinglipid-based nanotubules.

The present invention is also directed to a golf ball comprising a core;and a layer disposed concentrically about the core; wherein at least oneof the core or the layer is formed of a polymer composition comprising alipid-based nanotubule-encapsulated healing agent present in an amountbetween about 0.1% and about 20.0% of the composition by weight. In oneembodiment, the layer includes the lipid-based nanotubules and is anouter core layer, an inner cover layer, or an outer cover layer. Inanother embodiment, the core comprises a center and an outer core layerincluding the lipid-based nanotubules. In a preferred embodiment, thecore includes a base rubber and an organosulfur compound.

The core typically has an outer diameter of between about 1.5 inches andabout 1.62 inches. The composition can include an ionomer having acidgroups that have been 100% neutralized by a salt of an organic acid, acation source, or a suitable base thereof. The polymer includesthermoplastics, thermosets, ionomers and acid precursors; polyolefins;non-ionomers, polysaccharides; polyesters; polyamides; polypeptides;polyurethanes; polyureas, polyethylenes; polypropylenes;polyvinylchlorides; polystyrenes; polyphenols; polyvinyl pyrollidones;polyvinyl alcohols; ethylcelluloses; gar gums; metallocene-catalyzedpolymers; polyvinyl formal resins; water soluble epoxy resins;urea-formaldehydes; polylysines; chitosans; polyvinyl acetates; polymerscontaining α,β-unsaturated carboxylic acid groups, or the salts thereof;polycarbonates; polyarylates; polyimides; polyphenylene oxides;polyethers; silicones; polysiloxanes; polyisoprenes; block copoly(etheror ester-amides); block copoly(ether or ester-esters); polysulfones;reaction injection moldable thermoplastic and thermoset polymers; blockcopolymers of styrene-butadiene; dynamically vulcanizedethylene-propylene rubbers; polyvinylidenefluorids;acrylocnitrile-butadiene styrene copolymers; epoxy resins; acrylics; orpolybutadienes.

The healing agent generally includes a polycyclic organic moiety or itsfunctionalized derivatives. Additionally, the composition furtherincludes a catalyst. Preferably, the catalyst includes a Grubb'scatalyst, a ruthenium-based catalyst, an iron-based catalyst, an osmiumcatalyst, a living polymerization catalyst, a transition metal catalyst,or a mixture thereof.

The nanotubule should be configured to release the healing agent at aconstant rate and can further include a solubility modifier in an amountsufficient to alter the rate of release of the healing agent. Thecatalyst may also be encapsulated in the lipid-based nanotubules, whichpreferably have an inner diameter of from about 50 nm to about 1 μm,more preferably from about 200 nm to about 800 nm. The nanotubules alsoshould have a length of from about 1 pm to about 1 mm, more preferablyfrom about 10 μm to about 200 μm. In a preferred embodiment, the polymercomposition includes between about 5% and about 70% nanotubules.Ideally, the layer is an outer cover layer and includes saturated orunsaturated polyureas, polyurethanes, polyurethane-ureas,polyurea-urethanes, or epoxies.

The present invention is also directed to a golf ball comprising a core;an intermediate layer disposed about the core; a cover disposed adjacentto the intermediate layer; and a coating layer disposed adjacent to thecover; wherein the cover is comprised of lipid-basednanotubule-encapsulated healing agent for controlled release of thehealing agent into at least one of the adjacent intermediate or coatinglayers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The golf balls of the present invention may comprise any of a variety ofconstructions, from a simple one-piece solid ball, to a two-piece ballformed of a core and cover, to a three piece dual core single cover toany multi-piece construction, but preferably include a core formed of acenter and at least one outer core layer and a cover formed of an outercover layer and at least one inner cover layer. The core and/or thecover layers may be formed of more than one layer and an intermediate ormantle layer may be disposed between the core and the cover of the golfball. The innermost portion of the core, while preferably solid, may bea hollow or a liquid-, gel-, or air-filled sphere. As with the core, thecover layers may also comprise a plurality of layers, at least one ofwhich may be an adhesive or coupling layer. The layers may be continuousor non-continuous (i.e., grid-like). The core may also comprise a solidor liquid filled center around which many yards of a tensionedelastomeric material are wound.

The present invention is directed to the above-described cores, layers,and covers comprising lipid-based nanotubules. Lipid tubules are aself-organizing system in which surfactants crystallize into tightlypacked bilayers that spontaneously form cylinders less than 1 μm indiameter. These novel cylindrical lipid structures, called nanotubules,can be used to entrap and release a variety of active compounds intosurrounding materials. This approach to microencapsulation andcontrolled release has been shown to be effective for pharmaceuticaldrugs and for natural and man-made agents that are active in theprevention a number of undesirable properties, such as bio-fouling. Thisinvention is directed to the controlled release of desirable activeagents or compounds, microencapsulated in nanotubules, by theirdispersion in golf ball coatings, paints, adhesives, and componentcompositions. The tubules can be dispersed wet, aqueous orsolvent-based, or dry, if robustness is required.

Suitable tubules include those formed by the self organization ofpolymerizable lipid-based molecules. The tubules are typically formedfrom diacetylinic phosphatidylcholine by several different techniques,such as heating the lipid above the phase transition temperaturefollowed by slow cooling. Alternatively, the tubules can be formed byheating the lipid above the phase transition temperature, rapidlycooling the lipid to about 0° C., raising the temperature above thephase transition temperature a second time, and slowly cooling it toroom temperature. Other additional methods of forming the nanotubules ofthe present invention are envisioned. Naturally occurring nanotubules,such as halloycite, are also suitable for the present invention.

Alternatively, the nanotubules may additionally contain a metal (on theinner and/or outer surfaces). The tubules can be metallized with anymetal (or alloy thereof) capable of being plated. Metal tubules may beprepared by plating a metal on a filament which is soluble in ahydrocarbon solvent, to form an outer layer of metal, and then removingthe central filament by exposure to a hydrocarbon solvent.Alternatively, a porous membrane may be plated with a metal to form alayer of metal on the inside surface of the pores, dissolution of themembrane, and collection of the metal tubules. Once coated with metal,the tubules are filtered to remove the solvent and are air dried to apowder form. At this point the tubules can be stirred into a coating,such as a paint or adhesive, by gentle agitation. If the tubules areprocessed to a wet stage and then solvent exchanged with a coatingcompatible solvent, the tubules can be mixed directly into a coating orcomposition with a diluent solvent.

A critical aspect of the tubules is, of course, their dimensions.Suitable inner diameters for range from about 50 nm to about 20 μm,preferably from about 100 nm to about 1 μm, and most preferably fromabout 200 nm to about 800 nm. The inner diameter of the tubules and thedesired time period of release may be controlled by varying theconditions used to produce the tubules. These include choice of activeagent, carrier, environment surrounding the tubule, and other componentsof the composition (if the tubules are present in a composition).Generally, the diameter of the tubule will be 2 to 1,000 times theaverage diameter of the active agent or compound, preferably 20 to 500times the average diameter. The nanotubules are not limited to those ofany specific length. For any given tubule the time of effectiveness willincrease with an increase in the length of the tubule. Generally, thetubules will be of a length ranging from about 1 μm to about 1 mm, moretypically from about 10 μm to about 200 82 m.

Because of the tight packing of the surfactants in tubules, themicrostructures should dissolve from their ends only. Since the size ofthe end (the only available surface area for removal of active agent) isconstant until the tubule is annihilated, a population of tubules ofuniform length will release surfactant at a constant rate. A controlledrate of release of a compound from a coating or polymer matrix can beachieved by creating a porous structure of controlled dimensions withina coating. The compound must migrate through the coating to reach theinner or outer environment or adjacent materials. This structure can becreated by adding to a coating (or polymer composition) an effectiveamount of between about 5% and about 70% of nanotubules that contain orare composed of the desired active agent or compound.

The tubules, which act as microvials, can be filled by a variety oftechniques including capillary action. Compounds and active agentsinclude UV absorbers, light stabilizers, bleaching agents, fluorophores,healing agents, and catalysts. Suitable UV absorbers and lightstabilizers are described in U.S. application Ser. No. 09/861,909, thedisclosure of which is incorporated herein, in its entirety, by expressreference thereto. Suitable healing agents are described in U.S.application Ser. No. 10/176,720, the disclosure of which is incorporatedherein, in its entirety, by express reference thereto.

In a preferred embodiment, the lipid-based nanotubules are filled withand encapsulate a healing agent. Any of the components of the golf ballsof the present invention can be formed, either partially or fully,polymeric compositions including the nanotubule-encapsulated healingagent. Preferably the polymer compositions include at least one of abase material and a nanotubule-encapsulated healing agent. For the basematerial, the bulk of the golf ball material can be a thermoplastic,such as thermoplastic polyurethanes and SURLYN®-type ionomers, or athermoset, such as thermoset polyurethanes or crosslinked polybutadiene.Microencapsulated healing agents are the “glue” that fixes themicro-cracks formed in the base material. These healing agents aretypically fluids, such as dicyclopentadiene (“DCPD”). DCPD is preferablyencapsulated in the lipid-based nanotubules that are spread throughoutthe polymeric or rubber base material. Preferably, there are at leastabout 100 nanotubules per cubic inch, preferably between about 100 and200 nanotubules per cubic inch.

In order to polymerize and “heal” upon time release from thenanotubules, the healing agent must come into contact with a catalyst. Apreferred catalyst, called Grubbs catalyst, is used for thisself-healing material. It is important that the catalyst and healingagent remain separated until they are needed to seal a crack. When amicro-crack forms in the base material, it will spread through thematerial. By doing so, this crack will rupture the nanotubules andrelease the healing agent. This healing agent will flow down through thecrack and will inevitably come into contact with the Grubbs catalyst,which initiates the polymerization process. This process will eventuallybond the crack closed. In one embodiment, the nanotubules encapsulatethe catalyst as well.

In a preferred embodiment, the self-healing polymer blend has a flexuralmodulus of from about 2,000 to about 200,000 psi and containsnanotubules filled with dicyclopentadiene, dicyclohexa (or penta orocta) diene, (a liquid tricyclic diolefin). A polymerization catalyst isdispersed throughout the cover (in one embodiment), preferably aruthenium carbene complex. One source of the Grubbs catalyst is fromStrem Chemicals, 7 Mulliken Way, Newburyport, Mass. The Grubbsruthenium-based catalyst is very efficient at initiating variousreactions including olefin metathesis with high functional grouptolerance. Other potential suitable catalysts include elements such asiron, osmium, rhodium, iridium, palladium and platinum. It is believedthat iron should have similar electronic behavior, which could lead to asuccessful iron based olefin metathesis catalyst. In addition, it isbelieved that the use of living (uninterrupted chain ends)polymerization catalysts is preferred, allowing multiple healingopportunities.

The rate of release of the compound as a function of area can be furthercontrolled by the “loading” of the nanotubules, the concentration of thecompound or agent contained in the tubules, the dimensions of thetubules, and solubility modifiers also contained within the nanotubules.The compound is chosen during the manufacture of the tubules, and itsrate of release can be further modified during encapsulation by theaddition of solubility modifiers such as glues, resins, polymers andother “slow release agents.”

The hardness and ablation rate of a coating is controlled by theselection of the resins used as the coating vehicle. Vinyl-resinmixtures, acrylics, polyurethanes, and epoxies have been usedsuccessfully for this purpose. Further control of the coating propertiesand the release rates of the toxicants can be controlled by theorientation and distribution of the tubules by two methods. Orientationcan be accomplished by coating the surface in the presence of a magneticor electrical field which creates a preferred orientation of the tubulesto the coated surface, either parallel or normal. In addition, incoatings where the film thickness is less than the average tubulelength, the tubules can be oriented parallel to the surface.

Because of the aspect ratio and size of the tubules, the tubules canfurther act to form, within the coating, a network which adds improvedphysical characteristics. At the least the tubules extend down into thesurface so that they are anchored in place. The ability to form acomposite structure within the coating may provide enhanced structuralproperties not normally associated with the coating or compositionwithin which the tubules are dispersed.

The present coatings and/or compositions (containing the nanotubules)may be applied to a surface by any conventional techniques. Thus, thecoating compositions may be applied by roller, brush, or spray over asuitable primer or barrier coating, if necessary. The tubules are easilydispersed in paint and may be applied by means commonly used in theapplication of paint coatings. In addition, the tubules may be dried,and metal or metallized tubules can be oxidized. Such oxidized tubulescan be charged and applied to oppositely charged surfaces byconventional powder coating technology. If the tubules are dispersed ina polymer blend or matrix, the composition may be further injection orcompression molded, as desired. Additionally, the nanotubules may bedispersed in any of the reactants in a casting or reaction injectionmolding process.

A carrier is used to “fill” the tubules with the desired compound oractive agent. The selection of the carrier is determined by theviscosity of the carrier and the solubility of the active agent in thecarrier. The carrier must possess a sufficiently low viscosity so thatit can fill the tubule as a result of capillary action.

If the agent is soluble or is mobile in the carrier, then the rate ofrelease depends on the diffusion rate and solubility of the agent in thecarrier and in the external matrix (if present). If the agent isinsoluble or immobile in the carrier, then the rate of release dependson the rate of release of the carrier itself from the tubule.

In the present context, release means delivery of the agent to asurrounding matrix (e.g., in a coating composition). Accordingly,suitable carriers include low molecular weight polymers and monomers.Specific examples of such polymers include polysaccharides; polyesters;polyamides; nylons; polypeptides; polyurethanes; polyureas,polyethylenes; polypropylenes; polyvinylchlorides; polystyrenes;polyphenols; polyvinyl pyrollidone; polyvinyl alcohol; ethylcellulose;gar gum; polyvinyl formal resin; water soluble epoxy resins;urea-formaldehyde; polylysine; chitosan; polyvinyl acetate andcopolymers; and mixtures thereof.

Other uses for the nanotubules may include adhesion; thin-layerenforcement or stability; custom indicia or novel cover layers (i.e.,metallized tubules blended with cover material, which, upon oxidation,form colored “swirls” or patterns); reactive identifiers (i.e., age,heat, moisture, impact frequency, etc.); inks; and dyes.

Methods and processes for forming selected microstructures havingpredetermined shape and dimension from surfactants are described in U.S.Pat. Nos. 4,877,501 and 4,990,291; methods necessary to coat tubular,spheroidal, and helical lipid microstructures with a range of metals aredescribed in U.S. Pat. No. 4,911,981; and tubules are useful in theproduction of coating compositions for the protection of surfaces cominginto contact with water, adhesive resins for the production of laminatedwood products, and devices for dispensing pesticides are described inU.S. Pat. No. 6,280,759, all of which are incorporated herein, in theirentirety, by express reference thereto.

Suitable polyurethane-type materials for blending with the nanotubulesof the present invention or by which any cover layer, preferably outercover layers may be formed if not blended with the nanotubules include,but are not limited to, polyurethanes, polyurethane-ureas,polyurea-urethanes, polyureas, or epoxies, that generally comprise thereaction product of at least one polyisocyanate, polyol, and at leastone curing agent. Any polyisocyanate available to one of ordinary skillin the art is suitable for use according to the invention. Exemplarypolyisocyanates include, but are not limited to, 4,4′-diphenylmethanediisocyanate (“MDI”); polymeric MDI; carbodiimide-modified liquid MDI;4,4′-dicyclohexylmethane diisocyanate (“H₁₂MDI”);p-phenylenediisocyanate (“PPDI”); m-phenylene diisocyanate (“MPDI”); toluenediisocyanate (“TDI”); 3,3′-dimethyl-4,4′-biphenylene diisocyanate(“TODI”); isophoronediisocyanate (“IPDI”); hexamethylene diisocyanate(“HDI”); naphthalene diisocyanate (“NDI”); xylene diisocyanate (“XDI”);p-tetramethylxylene diisocyanate (“p-TMXDI”); m-tetramethylxylenediisocyanate (“m-TMXDI”); ethylene diisocyanate;propylene-1,2-diisocyanate; tetramethylene-1,4-diisocyanate; cyclohexyldiisocyanate; 1,6-hexamethylene-diisocyanate (“HDI”);dodecane-1,12-diisocyanate; cyclobutane-1,3-diisocyanate;cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; methylcyclohexylene diisocyanate; triisocyanate of HDI; triisocyanate of2,4,4-trimethyl-1,6-hexane diisocyanate (“TMDI”); tetracenediisocyanate; napthalene diisocyanate; anthracene diisocyanate;isocyanurate of toluene diisocyanate; uretdione of hexamethylenediisocyanate; and mixtures thereof. Preferably, the polyisocyanateincludes MDI, PPDI, TDI, or a mixture thereof. It should be understoodthat, as used herein, the term “MDI” includes 4,4′-diphenylmethanediisocyanate, polymeric MDI, carbodiimide-modified liquid MDI, andmixtures thereof and, additionally, that the diisocyanate employed maybe “low free monomer,” understood by one of ordinary skill in the art tohave lower levels of “free” monomer isocyanate groups, typically lessthan about 0.1% free monomer groups. Examples of “low free monomer”diisocyanates include, but are not limited to Low Free Monomer MDI, LowFree Monomer TDI, and Low Free Monomer PPDI.

The polyisocyanate should have less than about 14% unreacted NCO groups.Preferably, the at least one polyisocyanate has no greater than about7.5% NCO, and more preferably, less than about 7.0%. It is wellunderstood in the art that the hardness of polyurethane can becorrelated to the percent of unreacted NCO groups.

Any polyol available to one of ordinary skill in the art is suitable foruse according to the invention. Exemplary polyols include, but are notlimited to, polyether polyols, hydroxy-terminated polybutadiene(including partially/fully hydrogenated derivatives), polyester polyols,polycaprolactone polyols, and polycarbonate polyols. In one preferredembodiment, the polyol includes a polyether polyol, such aspolytetramethylene ether glycol (“PTMEG”), polyethylene propyleneglycol, polyoxypropylene glycol, and mixtures thereof. The hydrocarbonchain can have saturated or unsaturated bonds and substituted orunsubstituted aromatic and cyclic groups. Preferably, the polyol of thepresent invention includes PTMEG.

Suitable polyester polyols include, but are not limited to, polyethyleneadipate glycol; polybutylene adipate glycol; polyethylene propyleneadipate glycol; o-phthalate-1,6-hexanediol; poly(hexamethylene adipate)glycol; and mixtures thereof. The hydrocarbon chain can have saturatedor unsaturated bonds, or substituted or unsubstituted aromatic andcyclic groups.

Suitable polycaprolactone polyols include, but are not limited to,1,6-hexanediol-initiated polycaprolactone, diethylene glycol initiatedpolycaprolactone, trimethylol propane initiated polycaprolactone,neopentyl glycol initiated polycaprolactone, 1,4-butanediol-initiatedpolycaprolactone, PTMEG-initiated polycaprolactone, and mixturesthereof. The hydrocarbon chain can have saturated or unsaturated bonds,or substituted or unsubstituted aromatic and cyclic groups.

Suitable polycarbonates include, but are not limited to, polyphthalatecarbonate and poly(hexamethylene carbonate) glycol. The hydrocarbonchain can have saturated or unsaturated bonds, or substituted orunsubstituted aromatic and cyclic groups.

Polyamine curatives are also suitable for use in polyurethane covers.Preferred polyamine curatives include, but are not limited to,3,5-dimethylthio-2,4-toluenediamine and isomers thereof;3,5-diethyltoluene-2,4-diamine and isomers thereof, such as3,5-diethyltoluene-2,6-diamine;4,4′-bis-(sec-butylamino)-diphenylmethane;1,4-bis-(sec-butylamino)-benzene, 4,4′-methylene-bis-(2-chloroaniline);4,4′-methylene-bis-(3-chloro-2,6-diethylaniline) (“MCDEA”);polytetramethyleneoxide-di-p-aminobenzoate; N,N′-dialkyldiamino diphenylmethane; p,p′-methylene dianiline (“MDA”); m-phenylenediamine (“MPDA”);4,4′-methylene-bis-(2-chloroaniline) (“MOCA”);4,4′-methylene-bis-(2,6-diethylaniline) (“MDEA”);4,4′-methylene-bis-(2,3-dichloroaniline) (“MDCA”);4,4′-diamino-3,3′-diethyl-5,5′-dimethyl diphenylmethane;2,2′,3,3′-tetrachloro diamino diphenylmethane; trimethylene glycoldi-p-aminobenzoate; and mixtures thereof. Preferably, the curing agentof the present invention includes 3,5-dimethylthio-2,4-toluenediamineand isomers thereof, such as ETHACURE® 300, commercially available fromAlbermarle Corporation of Baton Rouge, La. Suitable polyamine curativesinclude both primary and secondary amines.

At least one of a diol, triol, tetraol, or hydroxy-terminated curativesmay be added to the aforementioned polyurethane composition. Suitablediol, triol, and tetraol groups include ethylene glycol; diethyleneglycol; polyethylene glycol; propylene glycol; polypropylene glycol;lower molecular weight polytetramethylene ether glycol;1,3-bis(2-hydroxyethoxy) benzene; 1,3-bis-[2-(2-hydroxyethoxy)ethoxy]benzene; 1,3-bis-{2-[2-(2-hydroxyethoxy) ethoxy]ethoxy}benzene;1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol;resorcinol-di-(β-hydroxyethyl) ether; hydroquinone-di-(β-hydroxyethyl)ether; and mixtures thereof. Preferred hydroxy-terminated curativesinclude 1,3-bis(2-hydroxyethoxy) benzene; 1,3-bis-[2-(2-hydroxyethoxy)ethoxy]benzene; 1,3-bis-{2-[2-(2-hydroxyethoxy) ethoxy]ethoxy}benzene;1,4-butanediol, and mixtures thereof.

Both the hydroxy-terminated and amine curatives can include one or moresaturated, unsaturated, aromatic, and cyclic groups. Additionally, thehydroxy-terminated and amine curatives can include one or more halogengroups. The polyurethane composition can be formed with a blend ormixture of curing agents. If desired, however, the polyurethanecomposition may be formed with a single curing agent.

In a particularly preferred embodiment of the present invention,saturated (aliphatic) polyurethanes are used to form cover layers,preferably the outer cover layer. The thermoset polyurethanes may becastable, reaction injection moldable, sprayable, or applied in alaminate form or by any technical known in the art. The thermoplasticpolyurethanes may be processed using any number of compression orinjection techniques. In one embodiment, the saturated polyurethanes aresubstantially free of aromatic groups or moieties.

Saturated diisocyanates which can be used include, but are not limitedto, ethylene diisocyanate; propylene-1,2-diisocyanate;tetramethylene-1,4-diisocyanate; 1,6-hexamethylene-diisocyanate;2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylenediisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethanediisocyanate; cyclobutane-1,3-diisocyanate;cyclohexane-1,3-diisocyanate; cyclohexane-1,4-diisocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane; isophoronediisocyanate (“IPDI”); methyl cyclohexylene diisocyanate; triisocyanateof HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexane diisocyanate(“TMDI”). The most preferred saturated diisocyanates are4,4′-dicyclohexylmethane diisocyanate and isophorone diisocyanate(“IPDI”).

Saturated polyols which are appropriate for use in this inventioninclude, but are not limited to, polyether polyols such aspolytetramethylene ether glycol and poly(oxypropylene) glycol. Suitablesaturated polyester polyols include polyethylene adipate glycol,polyethylene propylene adipate glycol, polybutylene adipate glycol,polycarbonate polyol and ethylene oxide-capped polyoxypropylene diols.Saturated polycaprolactone polyols which are useful in the inventioninclude diethylene glycol initiated polycaprolactone, 1,4-butanediolinitiated polycaprolactone, 1,6-hexanediol initiated polycaprolactone;trimethylol propane initiated polycaprolactone, neopentyl glycolinitiated polycaprolactone, PTMEG-initiated polycaprolactone. The mostpreferred saturated polyols are PTMEG and PTMEG-initiatedpolycaprolactone.

Suitable saturated curatives include 1,4-butanediol, ethylene glycol,diethylene glycol, polytetramethylene ether glycol, propylene glycol;trimethanolpropane; tetra-(2-hydroxypropyl)-ethylenediamine; isomers andmixtures of isomers of cyclohexyldimethylol, isomers and mixtures ofisomers of cyclohexane bis(methylamine); triisopropanolamine, ethylenediamine, diethylene triamine, triethylene tetramine, tetraethylenepentamine, 4,4′-dicyclohexylmethane diamine,2,2,4-trimethyl-1,6-hexanediamine; 2,4,4-trimethyl-1,6-hexanediamine;diethyleneglycol di-(aminopropyl)ether;4,4′-bis-(sec-butylamino)-dicyclohexylmethane;1,2-bis-(sec-butylamino)cyclohexane;1,4-bis-(sec-butylamino)cyclohexane; isophorone diamine, hexamethylenediamine, propylene diamine, 1-methyl-2,4-cyclohexyl diamine,1-methyl-2,6-cyclohexyl diamine, 1,3-diaminopropane, dimethylaminopropylamine, diethylamino propylamine, imido-bis-propylamine, isomersand mixtures of isomers of diaminocyclohexane, monoethanolamine,diethanolamine, triethanolamine, monoisopropanolamine, anddiisopropanolamine. The most preferred saturated curatives are1,4-butanediol, 1,4-cyclohexyldimethylol and4,4′-bis-(sec-butylamino)-dicyclohexylmethane.

Suitable catalysts include, but are not limited to bismuth catalyst,oleic acid, triethylenediamine (DABCO®-33LV), di-butyltin dilaurate(DABCO®-T12) and acetic acid. The most preferred catalyst is di-butyltindilaurate (DABCO®-T12). DABCO® materials are manufactured by AirProducts and Chemicals, Inc.

It is well known in the art that if the saturated polyurethane materialsare to be blended with other thermoplastics, care must be taken in theformulation process so as to produce an end product which isthermoplastic in nature. Thermoplastic materials may be blended withother thermoplastic materials, but thermosetting materials are difficultif not impossible to blend homogeneously after the thermosettingmaterials are formed. Preferably, the saturated polyurethane comprisesfrom about 1 to about 100%, more preferably from about 10 to about 75%of the cover composition and/or the intermediate layer composition.About 90 to about 10%, more preferably from about 90 to about 25% of thecover and/or the intermediate layer composition is comprised of one ormore other polymers and/or other materials as described below. Suchpolymers include, but are not limited to polyurethane/polyurea ionomers,polyurethanes or polyureas, epoxy resins, polyethylenes, polyamides andpolyesters, polycarbonates and polyacrylin. Unless otherwise statedherein, all percentages are given in percent by weight of the totalcomposition of the golf ball layer in question.

Polyurethane prepolymers are produced by combining at least one polyol,such as a polyether, polycaprolactone, polycarbonate or a polyester, andat least one isocyanate. Thermosetting polyurethanes are obtained bycuring at least one polyurethane prepolymer with a curing agent selectedfrom a polyamine, triol or tetraol. Thermoplastic polyurethanes areobtained by curing at least one polyurethane prepolymer with a diolcuring agent. The choice of the curatives is critical because someurethane elastomers that are cured with a diol and/or blends of diols donot produce urethane elastomers with the impact resistance required in agolf ball cover. Blending the polyamine curatives with diol curedurethane elastomeric formulations leads to the production of thermoseturethanes with improved impact and cut resistance. Other suitablethermoplastic polyurethane resins include those disclosed in U.S. Pat.No. 6,235,830, which is incorporated herein, in its entirety, by expressreference thereto.

The nanotubules may be included in the golf ball cores or, if thenanotubules are used in other components of the golf ball, the cores maybe formed of conventional materials. The cores are substantially solidand form a center of the golf ball. The cores may also contain aliquid-, gas-, or gel-filled center. The cores of the present inventionare surrounded by a single-layer or multiple-layer core or cover layersand are, optionally, painted, especially when a non-aliphatic ornon-saturated polyurethane cover is employed. The balls may also includeintermediate layers of molded or wound material as known by those ofordinary skill in the art. The present invention is therefore notlimited to incorporating the cores into any particular golf ballconstruction and the present cores can be used in any constructions.

The materials for solid cores include compositions having a base rubber,a crosslinking agent, a filler, a halogenated organosulfur compound, anda co-crosslinking or initiator agent. The base rubber typically includesnatural or synthetic rubbers. A preferred base rubber is1,4-polybutadiene having a cis-structure of at least 40%, morepreferably at least about 90%, and most preferably at least about 95%.Most preferably, the base rubber comprises high-Mooney-viscosity rubber.Preferably, the base rubber has a Mooney viscosity greater than about35, more preferably greater than about 50. Preferably, the polybutadienerubber has a molecular weight greater than about 400,000 and apolydispersity of no greater than about 2. Examples of desirablepolybutadiene rubbers include BUNA® CB22 and BUNA® CB23, commerciallyavailable from Bayer of Akron, Ohio; UBEPOL® 360L and UBEPOL® 150L,commercially available from UBE Industries of Tokyo, Japan; andCARIFLEX® BCP820 and CARIFLEX® BCP824, commercially available from Shellof Houston, Tex. If desired, the polybutadiene can also be mixed withother elastomers known in the art such as natural rubber, polyisoprenerubber and/or styrene-butadiene rubber in order to modify the propertiesof the core.

The crosslinking agent includes a metal salt, such as a zinc salt or amagnesium unsaturated fatty acid, such as acrylic or methacrylic acid,having 3 to 8 carbon atoms. Examples include, but are not limited to,one or more metal salt diacrylates, dimethacrylates, andmonomethacrylates, wherein the metal is magnesium, calcium, zinc,aluminum, sodium, lithium, or nickel. Preferred acrylates include zincacrylate, zinc diacrylate, zinc methacrylate, zinc dimethacrylate, andmixtures thereof. The crosslinking agent is typically present in anamount greater than about 10 parts per hundred (“pph”) parts of the basepolymer, preferably from about 20 to 40 pph of the base polymer, morepreferably from about 25 to 35 pph of the base polymer.

The initiator agent can be any known polymerization initiator whichdecomposes during the cure cycle. Suitable initiators include organicperoxide compounds, such as dicumyl peroxide; 1,1-di(t-butylperoxy)3,3,5-trimethyl cyclohexane; α,α-bis (t-butylperoxy) diisopropylbenzene;2,5-dimethyl-2,5 di(t-butylperoxy) hexane; di-t-butyl peroxide; andmixtures thereof. Other examples include, but are not limited to, VAROX®231XL and Varox® DCP-R, commercially available from Elf Atochem ofPhiladelphia, Pa.; PERKODOX® BC and PERKODOX® 14, commercially availablefrom Akzo Nobel of Chicago, Ill.; and ELASTOCHEM® DCP-70, commerciallyavailable from Rhein Chemie of Trenton, N.J.

It is well known that peroxides are available in a variety of formshaving different activity. The activity is typically defined by the“active oxygen content.” For example, PERKODOX® BC peroxide is 98%active and has an active oxygen content of 5.80%, whereas PERKODOX®DCP-70 is 70% active and has an active oxygen content of 4.18%. If theperoxide is present in pure form, it is preferably present in an amountof at least about 0.25 pph, more preferably between about 0.35 pph andabout 2.5 pph, and most preferably between about 0.5 pph and about 2pph. Peroxides are also available in concentrate form, which arewell-known to have differing activities, as described above. In thiscase, if concentrate peroxides are employed in the present invention,one skilled in the art would know that the concentrations suitable forpure peroxides are easily adjusted for concentrate peroxides by dividingby the activity. For example, 2 pph of a pure peroxide is equivalent 4pph of a concentrate peroxide that is 50% active (i.e., 2 divided by0.5=4).

The halogenated organosulfur compounds of the present invention include,but are not limited to those having the following general formula:

where R₁-R₅ can be C₁-C₈ alkyl groups; halogen groups; thiol groups(—SH), carboxylated groups; sulfonated groups; and hydrogen; in anyorder; and also pentafluorothiophenol; 2-fluorothiophenol;3-fluorothiophenol; 4-fluorothiophenol; 2,3-fluorothiophenol;2,4-fluorothiophenol; 3,4-fluorothiophenol; 3,5-fluorothiophenol2,3,4-fluorothiophenol; 3,4,5-fluorothiophenol;2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetrafluorothiophenol;4-chlorotetrafluorothiophenol; pentachlorothiophenol;2-chlorothiophenol; 3-chlorothiophenol; 4-chlorothiophenol;2,3-chlorothiophenol; 2,4-chlorothiophenol; 3,4-chlorothiophenol;3,5-chlorothiophenol; 2,3,4-chlorothiophenol; 3,4,5-chlorothiophenol;2,3,4,5-tetrachlorothiophenol; 2,3,5,6-tetrachlorothiophenol;pentabromothiophenol; 2-bromothiophenol; 3-bromothiophenol;4-bromothiophenol; 2,3-bromothiophenol; 2,4-bromothiophenol;3,4-bromothiophenol; 3,5-bromothiophenol; 2,3,4-bromothiophenol;3,4,5-bromothiophenol; 2,3,4,5-tetrabromothiophenol;2,3,5,6-tetrabromothiophenol; pentaiodothiophenol; 2-iodothiophenol;3-iodothiophenol; 4-iodothiophenol; 2,3-iodothiophenol;2,4-iodothiophenol; 3,4-iodothiophenol; 3,5-iodothiophenol;2,3,4-iodothiophenol; 3,4,5-iodothiophenol; 2,3,4,5-tetraiodothiophenol;2,3,5,6-tetraiodothiophenoland; and their zinc salts. Preferably, thehalogenated organosulfur compound is pentachlorothiophenol, which iscommercially available in neat form or under the tradename STRUKTOL®, aclay-based carrier containing the sulfur compound pentachlorothiophenolloaded at 45 percent (correlating to 2.4 parts PCTP). STRUKTOL® iscommercially available from Struktol Company of America of Stow, Ohio.PCTP is commercially available in neat form from eChinachem of SanFrancisco, Calif. and in the salt form from eChinachem of San Francisco,Calif. Most preferably, the halogenated organosulfur compound is thezinc salt of pentachlorothiophenol, which is commercially available fromeChinachem of San Francisco, Calif. The halogenated organosulfurcompounds of the present invention are preferably present in an amountgreater than about 2.2 pph, more preferably between about 2.3 pph andabout 5 pph, and most preferably between about 2.3 and about 4 pph.

Fillers typically include materials such as tungsten, zinc oxide, bariumsulfate, silica, calcium carbonate, zinc carbonate, metals, metal oxidesand salts, regrind (recycled core material typically ground to about 30mesh particle), high-Mooney-viscosity rubber regrind, and the like.Fillers added to one or more portions of the golf ball typically includeprocessing aids or compounds to affect rheological and mixingproperties, density-modifying fillers, tear strength, or reinforcementfillers, and the like. The fillers are generally inorganic, and suitablefillers include numerous metals or metal oxides, such as zinc oxide andtin oxide, as well as barium sulfate, zinc sulfate, calcium carbonate,barium carbonate, clay, tungsten, tungsten carbide, an array of silicas,and mixtures thereof. Fillers may also include various foaming agents orblowing agents which may be readily selected by one of ordinary skill inthe art. Fillers may include polymeric, ceramic, metal, and glassmicrospheres may be solid or hollow, and filled or unfilled. Fillers aretypically also added to one or more portions of the golf ball to modifythe density thereof to conform to uniform golf ball standards. Fillersmay also be used to modify the weight of the center or at least oneadditional layer for specialty balls, e.g., a lower weight ball ispreferred for a player having a low swing speed.

The invention also includes a method to convert the cis- isomer of thepolybutadiene resilient polymer component to the trans- isomer during amolding cycle and to form a golf ball. A variety of methods andmaterials suitable for cis-to-trans conversion have been disclosed inU.S. Pat. No. 6,162,135 and U.S. application Ser. No. 09/461,736, filedDec. 16, 1999; Ser. No. 09/458,676, filed Dec. 10, 1999; and Ser. No.09/461,421, filed Dec. 16, 1999, each of which are incorporated herein,in their entirety, by reference. Plasma treatment and coatings andadhesives, including silanes and silane coupling agents, are alsoenvisioned to aid in adhesion of the layers of the present invention andmay also be “loaded” into the nanotubules.

Any of the cover layers may also be formed from polymers containingα,β-unsaturated carboxylic acid groups, or the salts thereof, that havebeen 100 percent neutralized by organic fatty acids. The acid moietiesof the highly-neutralized polymers (“HNP”), typically ethylene-basedionomers, are preferably neutralized greater than about 70%, morepreferably greater than about 90%, and most preferably at least about100%. The HNP's can be also be blended with a second polymer component,which, if containing an acid group, may be neutralized in a conventionalmanner, by the organic fatty acids of the present invention, or both.The second polymer component, which may be partially or fullyneutralized, preferably comprises ionomeric copolymers and terpolymers,ionomer precursors, thermoplastics, polyamides, polycarbonates,polyesters, polyurethanes, polyureas, thermoplastic elastomers,polybutadiene rubber, balata, metallocene-catalyzed polymers (graftedand non-grafted), single-site polymers, high-crystalline acid polymers,cationic ionomers, and the like.

A variety of conventional components can be added to the compositions ofthe present invention. These include, but are not limited to, whitepigment such as TiO₂, ZnO, optical brighteners, surfactants, processingaids, foaming agents, density-controlling fillers, UV stabilizers andlight stabilizers. Saturated polyurethanes are resistant todiscoloration. However, they are not immune to deterioration in theirmechanical properties upon weathering. Addition of UV absorbers andlight stabilizers to any of the above compositions and, in particular,the polyurethane compositions, help to maintain the tensile strength,elongation, and color stability. Suitable UV absorbers and lightstabilizers include TINUVIN® 328, TINUVIN® 213, TINUVIN® 765, TINUVIN®770 and TINUVIN® 622. The preferred UV absorber is TINUVIN® 328, and thepreferred light stabilizer is TINUVIN® 765. TINUVIN® products areavailable from Ciba-Geigy. Dyes, as well as optical brighteners andfluorescent pigments may also be included in the golf ball coversproduced with polymers formed according to the present invention. Suchadditional ingredients may be added in any amounts that will achievetheir desired purpose.

Any method known to one of ordinary skill in the art may be used to formthe polyurethanes of the present invention. One commonly employedmethod, known in the art as a one-shot method, involves concurrentmixing of the polyisocyanate, polyol, and curing agent. This methodresults in a mixture that is inhomogenous (more random) and affords themanufacturer less control over the molecular structure of the resultantcomposition. A preferred method of mixing is known as a prepolymermethod. In this method, the polyisocyanate and the polyol are mixedseparately prior to addition of the curing agent. This method affords amore homogeneous mixture resulting in a more consistent polymercomposition. Other methods suitable for forming the layers of thepresent invention include reaction injection molding (“RIM”), liquidinjection molding (“LIM”), and pre-reacting the components to form aninjection moldable thermoplastic polyurethane and then injectionmolding, all of which are known to one of ordinary skill in the art.

It has been found by the present invention that the use of a castable,reactive material, which is applied in a fluid form, makes it possibleto obtain very thin outer cover layers on golf balls. Specifically, ithas been found that castable, reactive liquids, which react to form aurethane elastomer material, provide desirable very thin outer coverlayers.

The castable, reactive liquid employed to form the urethane elastomermaterial can be applied over the core using a variety of applicationtechniques such as spraying, dipping, spin coating, or flow coatingmethods which are well known in the art. An example of a suitablecoating technique is that which is disclosed in U.S. Pat. No. 5,733,428,the disclosure of which is hereby incorporated by reference in itsentirety in the present application.

The outer cover is preferably formed around the inner cover, if present,by mixing and introducing the material in the mold halves. It isimportant that the viscosity be measured over time, so that thesubsequent steps of filling each mold half, introducing the core intoone half and closing the mold can be properly timed for accomplishingcentering of the core cover halves fusion and achieving overalluniformity. Suitable viscosity range of the curing urethane mix forintroducing cores into the mold halves is determined to be approximatelybetween about 2,000 cP and about 30,000 cP, with the preferred range ofabout 8,000 cP to about 15,000 cP.

To start the cover formation, mixing of the prepolymer and curative isaccomplished in motorized mixer including mixing head by feeding throughlines metered amounts of curative and prepolymer. Top preheated moldhalves are filled and placed in fixture units using centering pinsmoving into holes in each mold. At a later time, a bottom mold half or aseries of bottom mold halves have similar mixture amounts introducedinto the cavity. After the reacting materials have resided in top moldhalves for about 40 to about 80 seconds, a core is lowered at acontrolled speed into the gelling reacting mixture.

A ball cup holds the ball core through reduced pressure (or partialvacuum). Upon location of the coated core in the halves of the moldafter gelling for about 40 to about 80 seconds, the vacuum is releasedallowing core to be released. The mold halves, with core and solidifiedcover half thereon, are removed from the centering fixture unit,inverted and mated with other mold halves which, at an appropriate timeearlier, have had a selected quantity of reacting polyurethaneprepolymer and curing agent introduced therein to commence gelling.

Similarly, U.S. Pat. No. 5,006,297 and U.S. Pat. No. 5,334,673 both alsodisclose suitable molding techniques which may be utilized to apply thecastable reactive liquids employed in the present invention. Further,U.S. Pat. Nos. 6,180,040 and 6,180,722 disclose methods of preparingdual core golf balls. The disclosures of these patents are herebyincorporated by reference in their entirety. However, the method of theinvention is not limited to the use of these techniques.

The resultant golf balls typically have a COR of greater than about0.75, preferably greater than about 0.8, and more preferably greaterthan about 0.81. In a preferred embodiment, the golf ball has a COR ofgreater than about 0.82. The golf balls also typically have an Atticompression of at least about 30, preferably from about 50 to 120, andmore preferably from about 55 to 85. A golf ball core layer, i.e.,either the innermost core or any enclosing core layer, typically has ahardness of at least about 5 Shore A, preferably between about 20 ShoreA and 80 Shore D, more preferably between about 30 Shore A and 65 ShoreD.

When golf balls are prepared according to the invention, they typicallywill have dimple coverage greater than about 60 percent, preferablygreater than about 70 percent, and more preferably greater than about 80percent. The flexural modulus of the cover on the golf balls, asmeasured by ASTM method D6272-98, Procedure B, is typically greater thanabout 100 psi, and is preferably from about 500 psi to 150,000 psi. Asdiscussed herein, the outer cover layer is preferably formed from arelatively soft polyurethane material. In particular, the material ofthe outer cover layer should have a material hardness, as measured byASTM-D2240, less than about 70 Shore D, more preferably between about 25and about 50 Shore D, and most preferably between about 40 and about 50Shore D. In a preferred embodiment, the outer cover has a Shore Dhardness of between about 45 and about 48. The inner cover layerpreferably has a material hardness of less than about 70 Shore D, morepreferably between about 5 and about 70 Shore D, and most preferably,between about 20 and about 65 Shore D.

The core of the present invention has an Atti compression of less thanabout 120, more preferably, between about 20 and about 100, and mostpreferably, between about 40 and about 80. In an alternative, lowcompression embodiment, the core has an Atti compression less than about20, more preferably less than about 10, and most preferably, 0.

The overall outer diameter (“OD”) of the core is less than about 1.650inches, preferably, no greater than 1.620 inches, more preferablybetween about 1.500 inches and about 1.610 inches, and most preferablybetween about 1.52 inches to about 1.60 inches. In one embodiment, thecore OD is between about 1.5 inches and about 1.59 inches. The OD of theinner cover layer is preferably between 1.580 inches and about 1.650inches, more preferably between about 1.590 inches to about 1.630inches, and most preferably between about 1.600 inches to about 1.630inches.

The present multilayer golf ball can have an overall diameter of anysize. Although the United States Golf Association (“USGA”)specifications limit the minimum size of a competition golf ball to1.680 inches. There is no specification as to the maximum diameter. Golfballs of any size, however, can be used for recreational play. Thepreferred diameter of the present golf balls is from about 1.680 inchesto about 1.800 inches. The more preferred diameter is from about 1.680inches to about 1.760 inches. The most preferred diameter is about 1.680inches to about 1.740 inches.

It should be understood, especially to one of ordinary skill in the art,that there is a fundamental difference between “material hardness” and“hardness, as measured directly on a golf ball.” Material hardness isdefined by the procedure set forth in ASTM-D2240 and generally involvesmeasuring the hardness of a flat “slab” or “button” formed of thematerial of which the hardness is to be measured. Hardness, whenmeasured directly on a golf ball (or other spherical surface) is acompletely different measurement and, therefore, results in a differenthardness value. This difference results from a number of factorsincluding, but not limited to, ball construction (i.e., core type,number of core and/or cover layers, etc.), ball (or sphere) diameter,and the material composition of adjacent layers. It should also beunderstood that the two measurement techniques are not linearly relatedand, therefore, one hardness value cannot easily be correlated to theother.

It is believed that golf balls made in accordance with the presentinvention will exhibit appreciably greater impact durability thanconventional golf balls. The polymers of the present invention may alsobe used in sporting equipment and, in particular, golf equipment, suchas golf club inserts (i.e., a putter insert), golf clubs and shafts,golf shoe components, and coatings golf equipment.

As used herein, the term “about,” used in connection with one or morenumbers or numerical ranges, should be understood to refer to all suchnumbers, including all numbers in a range.

While it is apparent that the illustrative embodiments of the inventionherein disclosed fulfills the objective stated above, it will beappreciated that numerous modifications and other embodiments may bedevised by those skilled in the art. Therefore, it will be understoodthat the appended claims are intended to cover all such modificationsand embodiments which come within the spirit and scope of the presentinvention.

1. A golf ball comprising: a core; and a layer disposed concentricallyabout the core; wherein at least one of the core or the layer is formedof a polymer composition comprising a lipid-basednanotubule-encapsulated healing agent present in an amount between about0.1% and about 20.0% of the composition by weight.
 2. The golf ball ofclaim 1, wherein the layer comprises the lipid-based nanotubules and isan outer core layer, an inner cover layer, or an outer cover layer. 3.The golf ball of claim 1, wherein the core comprises a center and anouter core layer comprising the lipid-based nanotubules.
 4. The golfball of claim 3, wherein the center comprises a base rubber and anorganosulfur compound.
 5. The golf ball of claim 1, wherein the core hasan outer diameter of between about 1.5 inches and about 1.62 inches. 6.The golf ball of claim 1, wherein the core or the polymer compositioncomprises an ionomer having acid groups that have been 100% neutralizedby a salt of an organic acid, a cation source, or a suitable basethereof.
 7. The golf ball of claim 1, wherein the polymer comprisesthermoplastics, thermosets, ionomers and acid precursors; polyolefins;non-ionomers, polysaccharides; polyesters; polyamides; polypeptides;polyurethanes; polyureas, polyethylenes; polypropylenes;polyvinylchlorides; polystyrenes; polyphenols; polyvinyl pyrollidones;polyvinyl alcohols; ethylcelluloses; gar gums; metallocene-catalyzedpolymers; polyvinyl formal resins; water soluble epoxy resins;urea-formaldehydes; polylysines; chitosans; polyvinyl acetates; polymerscontaining α,β-unsaturated carboxylic acid groups, or the salts thereof;polycarbonates; polyarylates; polyimides; polyphenylene oxides;polyethers; silicones; polysiloxanes; polyisoprenes; block copoly(etheror ester-amides); block copoly(ether or ester-esters); polysulfones;reaction injection moldable thermoplastic and thermoset polymers; blockcopolymers of styrene-butadiene; dynamically vulcanizedethylene-propylene rubbers; polyvinylidenefluorids;acrylocnitrile-butadiene styrene copolymers; epoxy resins; acrylics; orpolybutadienes.
 8. The golf ball of claim 1, wherein the healing agentcomprises a polycyclic organic moiety or its functionalized derivatives.9. The golf ball of claim 1, wherein the composition further comprises acatalyst.
 10. The golf ball of claim 9, wherein the catalyst comprises aGrubb's catalyst, a ruthenium-based catalyst, an iron-based catalyst, anosmium catalyst, a living polymerization catalyst, a transition metalcatalyst, or a mixture thereof.
 11. The golf ball of claim 1, whereinthe nanotubule is configured to release the healing agent at a constantrate.
 12. The golf ball of claim 11, wherein the nanotubule furthercomprises a solubility modifier in an amount sufficient to alter therate of release of the healing agent.
 13. The golf ball of claim 1,wherein the composition further comprises a lipid-basednanotubule-encapsulated catalyst.
 14. The golf ball of claim 1, whereinthe nanotubules have an inner diameter of from about 50 nm to about 1μm.
 15. The golf ball of claim 14, wherein the nanotubules have an innerdiameter of from about 200 nm to about 800 nm.
 16. The golf ball ofclaim 1, wherein the nanotubules have a length of from about 1 μm toabout 1 mm.
 17. The golf ball of claim 16, wherein the nanotubules havea length of from about 10 μm to about 200 μm.
 18. The golf ball of claim1, wherein the polymer composition comprises between about 5% and about70% nanotubules.
 19. The golf ball of claim 1, wherein the layer is anouter cover layer and comprises saturated or unsaturated polyureas,polyurethanes, polyurethane-ureas, polyurea-urethanes, or epoxies.
 20. Agolf ball comprising: a core; an intermediate layer disposed about thecore; a cover disposed adjacent to the intermediate layer; and a coatinglayer disposed adjacent to the cover; wherein the cover is comprised oflipid-based nanotubule-encapsulated healing agent for controlled releaseof the healing agent into at least one of the adjacent intermediate orcoating layers.